Control device for gas burner

ABSTRACT

A device for controlling gas burners which enables precise adjustment of the heating rate of the burner is disclosed. The device includes an energy regulator which adjusts the heating rate by alternate lighting and extinguishing of the burner in a more or less cyclic manner. In operation, a main control knob is set to obtain the operating rate required. This immediately energizes an electro-valve which feeds gas to a pilot. At the same time, a spark generator is energized to light the pilot light. Once the pilot is lit, a safety inverter turns the spark generator off. A second electro-valve is enabled a predetermined time thereafter and, under the control of the energy regulator, feeds gas to the burner. A thermostatically operated switch may also be placed in series between the energy regulator and the second electro-valve to provide additional control of the heating rate of the burner.

United States Patent 1191 1111 3,845,582

Capy 1 Nov. 5, 1974 CONTROL DEVICE FOR GAS BURNER 75 Inventor: Marcel CaOlivet, France Primary Exammer carron Dom) 1 py Attorney. Agent, orFirm-Sughrue, Rothwell, Mion, [73] Ass1gnee: Compagnie Europeene PourZinn & MacPeak LEquipment Menager CEPEM, Paris, France 57 ABSTRACT [22]Filed: Mar. 2, 1973 A device for controlling gas burners which enablesprecise adjustment of the heating rate of the burner is [21] Appl 337500disclosed. The device includes an energy regulator which adjusts theheating rate by alternate lighting and [30] Foreign Application PriorityData extinguishing of the burner in a more or less cyclic Mar. 3, 1972France 72.07474 manner- In Operation a main control knob is Set to June20, 1972 France 755518 btain the Operating Tate required- Thisimmediately energizes an electro-valve which feeds gas to a pilot. 52us. 01. 43/1, 431/46 At the Same time, a Spark generator is energized to51 Int. Cl. F23c 3/02 light the Pilot light Once the pilot is lit, asafety 5 1 w f Search 236/68 C 46 F 68 verter turns the spark generatoroff. A second electro- 431/45, 46 1 valve is enabled a predeterminedtime thereafter and, under the control of the energy regulator, feedsgas to 5 References Cited the burner. A thermostatically operated switchmay UNITED STATES PATENTS also be placed in series between the energyregulator and the second electro-valve to provide additional 5:22:23;control of the heating rate of the burner. 2:962:092 11/1960Thornberyiiiiiii...... 431/45 7 Claims, 2 Drawing Figures :1? 7 hi T l Jl l l l H e RE C CONTROL DEVICE FOR GAS BURNER BACKGROUND OF THEINVENTION and to have available a means for checking to see thatlighting has actually been effected and for stopping the gas input tothe burner in the case of accidental extinguishing.

Lighting may be caused directly by an electric spark (induction orpiezoelectric) generating device, or even by an electrical resistorbrought to a high temperature; it is then necessary to check thelighting of the flame by means of a device having no inertia, forexample, by using the electrical properties of ionised gases, or thelight radiation emitted by that flame; it is also possible to use a gaspilot placed close to the burner.

SUMMARY OF THE INVENTION The invention has for its object the provisionof a device for controlling gas burners, enabling the calorific output,that is, the heating rate of the said burner, to be adjusted. comprisingvarious elements including a device for lighting the gas burner and asafety device, further characterised in that the device for'controllingcomprises an energy regulator which adjusts the heating rate byalternate lighting a nd extinguishing of the said burner and ensures, onthe one hand and in a cyclic manner, the electrical feeding of a gasinlet electrovalve for the said burner and, on the other hand,continuously, at the instant of starting up, the electrical feeding ofthe various elements BRIEF DESCRIPTION OF THE DRAWINGS Othercharacteristics and advantages will become apparent from the followingdescription of examples of embodiment illustrated by the accompanyingdrawings, in which:

FIG. 1 is a wiring diagram of a control device using an energy regulatorcomprising a bipolar cut-out means; and

FIG. 2 is a wiring diagram of a control device using a singlepole energyregulator and a thermostatic element.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, B is a burner whosegas inlet is dependent on an electro-valve EV2; V is a pilot whose gasinlet is dependent on an electro-valve EVl, ISM is a mercury type safetyinvertor having a tank S heated by the pilot V, RT is a time delay relayand RE is an energy regulator having a bipolar cut-out means fed by analternating current mains, G is an induction type spark generatorsending out to 500 sparks per minute between an electrode E and the bodyof the pilot V electrically connected to ground; an indicator light L1enables the operation of the spark generator G to be indicated, or theuser to be warned, when the pilot, being extinguished, the safetyinvertor ISM stops the input of gas to the burner B and to the pilot V;an indicator light L2 connected with the energy regulator RE on the sideon which the electro-valve EV2 is installed enables the lighting orextinguishing of the burner B to be indicated.

The operation of the device is as follows: The user starts up theburnerby starting up the energy regulator RE by means of a control knobM, and sets that knob to obtain the operating rate required, the saidknob acting on a cam C for adjusting the distance of the bimetallicstrip bi of the energy regulator; such a regulator is known per se andthe operating thereof gives the man in the art no difficulty; the coil 1of the electrovalve EVl is then fed through a break contact R1 of thetime delay relay RT; the spark generator G being fed through a breakcontact R2 of the safety invertor ISM, provides for the lighting of thepilot V which heats the tank S of the safety invertor ISM, thisestablishing make contacts T2 and T3 of the said invertor; the said tankS is placed in such a way that it is heated by the pilot and not by theburner. The contact T2 enables the feeding of the coil 1 of theelectro-valve EVl without using the time delay relay RT, at the sametime as the spark generator G stops operating by the cutting off of itssupply; the time delay relay then comes into action and, by its makecontact T1, enables the feeding of the coil 2 of the electro-valveEV2,'the contact T3 of the safety invertor ISM being closed; the burnerB receiving gas is lit by the pilot V. After a certain time, the bimetallic strip bi of the energy regulator will operate, stopping thefeeding of the coil 2 of the electro-valve EV2; after a certain time,the bi-metallic strip bi, having cooled down, closes the electric feedcircuit of the coil 2, opening the electro-valve EV2 and the burner Boperates once more.

' To stop the burner, all that is necessary is to set the control knob Min the stop position, this cutting out the feeding of the energyregulator; the pilot is extinguished by the closing of the electro-valveEVl.

In FIG. 2, B is a burner whose gas inlet is dependent on anelectro-valve EV2, V is a pilot whose gas inlet is dependent on anelectro-valve EVl, ISM is a mercury type safety invertor having a tank Sheated by the pilot V, RT is a time-delay relay and RE is an energyregulator having single pole cut-out means fed by an alternating currentmains, G is an induction type spark generator sending out 10 to 500sparks per minute between an electrode E and the body of the pilot Velectrically connected to ground. Th is a thermostatic elementelectrovalve EV2 makes it possible to represent visually the operatingof the said electro-valve, hence of the gas burner B. i

The user starts up the operation of the device is as follows the burnerby setting the energy regulator REl by means of a control knob M, andpositions that knob to obtain the required operating rate, the said knobacting on an adjusting cam C regulating the distance of the bi-metallicstrip bi of the energy regulator; such a regulator is known per se andthe operating thereof gives the man in the art no difficulty; the coil 1of the electrovalve EVl is then fed through a break contact R1 of thetime delay relay RT; the spark generator G being fed through a breakcontact R2 of the safety invertor ISM provides for the lighting of thepilot V which heats the tank S of the safety invertor lSM, this bringingmake contacts T2 and T3 of the said invertor into play; the said tank Sis placed so that it is heated by the pilot and not by the burner. Thecontact T2 enables the feeding of the coil 1 of the electrovalve EVlwithout using the time delay relay RT, at the same time as the sparkgenerator stops operating due to the stopping of its electricity supply;the time delay relay then comes into action and, by its make contact Tl,enables the feeding of the coil 2 of the electro-valve EV2, the contactT3 of the safety invertor ISM being closed; the burner B receiving gasis lit by the pilot V. After a certain time, the bi-metallic strip bi ofthe energy regulator will operate, stopping the electricity supply ofthe coil 2 of the electrovalve EV2; after a certain time, when thebimetallic strip bi has cooled down, it closes the electricity supplycircuit of the coil 2 again, opening the electro-valve EV2, then theburner operates again.

If the temperature of the device heated by the burner B axceeds acertain value detected by the thermostatic element Th. the operation ofthe latter causes the opening of its contact Thl, this stopping theelectricity supply of the electro-valve EV2 of the gas burner B, hencethe input of gas to the said burner stops, as long as the contact Thl isnot closed, that is, as long as the temperature of the device protectedby the thermostatic element Th has not returned to a value lower thanthe operation value of the said element Th; when the temperature haslowered, the contact Th1 closes and the electro-valve is again fedthrough the energy regulator.

To stop the burner. all that is needed is the setting of the controlknob M in the stop position, this stopping the supply to the energyregulator; the pilot is extinguished by the closing of the electro-valveEVl.

The thermostatic element may be constituted by any device such as, forexample, a thermo-electric couple or a thermistance connected with thatrelay having an opening type contact, or it may even be constituted by asafety invertor similar to the invertor ISM for controlling the lightingof the pilot.

The device according to the invention is applied to any burner whoseheating rate is to be controlled, that is, in which the calorific outputis to be modulated, by adjusting the lighting and extinguishing periods,as is the case in numerous appliances such as ovens, waterheaters, wateror air heat generators, hot-plates made of metallic or refractorymateriels, with which kitchen ranges. for example, are equipped; whenthe burner is covered, as is the case, for example, in certain kitchenranges, the burner and the pilot will, to great advantage, be of thefull air type.

The energy regulator may be fed also through a timing device TD whichwill regulate the total operating time of the gas burner; The timingdevice controls the starting up of the burner at a determined instantand the stopping of that burner at a determined instant in a well-knownthe heating rate being fixed by the positioning of the energy regulatorby means of the manual control knob M.

it must be understood that the invention is in no way limited to theexamples of embodiment described and illustrated, and that it would bepossible, without going beyond the scope of the invention, to replacecertain means by equivalent means.

I claim:

1. In a gas burner system including a main burner and a pilot burner forlighting said main burner, a safety device for controlling said mainburner comprising:

a first gas inlet elcctro-valve for supplying gas to said main burner,

a safety invertor including switch means and heat responsive means inclose proximity to said pilot burner for operating said switch means inresponse to a pilot flame,

a time delay switch, and

energy regulator means connected to energize said first gas inletelectro-valve through said time delay switch and said safety invertorswitch means, said energy regulator means including electrically heatedbi-metallic switch means for intermittently opening and closing thecircuit to said first gas inlet electro-valve, thereby adjusting theheating rate of said main burner by alternately lighting andextinguishing said main burner in a cyclic manner, said time delayswitch being continuously energized through said energy regulator meanswhen it is turned on.

2. A device for controlling said main burner according to claim 1,further comprising a second gas inlet electro-valve, said second gasinlet electro-valve being initially connected to said energy regulatormeans through said time delay switch wherein said second electro-valveis energized through said energy regulator means and said delay switchwhen said energy regulator means is turned on and after the operation ofsaid time delay switch said second gas inlet electro-valve beingconnected to said energy regulator means through said safety invertorswitch means, said first electro-valve being disconnected from saidenergy regulator by said safety invertor switch means if said pilotmeans is extinguished thereby removing heat from said safety invertorheat responsive means.

3. A device for controlling said main burner according to claim 1wherein bi-metallic strip is heated by a resistor supplied with electriccurrent through an opening contact of the said bi-metallic strip.

4. A device for controlling said main burner according to claim 1wherein said energy regulator means is a bi-polar cut-out regulator.

5. A device for controlling said main burner according to claim Iwherein said energy regulator means is a single-pole cut-out regulator.

6. A device for controlling said main burner according to claim 1further comprising a thermostatic temperature detection means for adevice heated by said main burner wherein an opening contact of saidthermostatic means is inserted in series in the electric feed circuit ofsaid first gas inlet electro-valve of said main burner.

7. A device for controlling said main burner according to claim 4,further including a timing device inserted in a supply means for saidenergy regulator

1. In a gas burner system including a main burner and a pilot burner forlighting said main burner, a safety device for controlling said mainburner comprising: a first gas inlet electro-valve for supplying gas tosaid main burner, a safety invertor including switch means and heatresponsive means in close proximity to said pilot burner for operatingsaid switch means in response to a pilot flame, a time delay switch, andenergy regulator means connected to energize said first gas inletelectro-valve through said time delay switch and said safety invertorswitch means, said energy regulator means including electrically heatedbi-metallic switch means for intermittently opening and closing thecircuit to said first gas inlet electro-valve, thereby adjusting theheating rate of said main burner by alternately lighting andextinguishing said main burner in a cyclic manner, said time delayswitch being continuously energized through said energy regulator meanswhen it is turned on.
 2. A device for controlling said main burneraccording to claim 1, further comprising a second gas inletelectro-valve, said second gas inlet electro-valve being initiallyconnected to said energy regulator means through said time delay switchwherein said second electro-valve is energized through said energyregulator means and said delay switch when said energy regulator meansis turned on and after the operation of said time delay switch saidsecond gas inlet electro-valve being connected to said energy regulatormeans through said safety invertor switch means, said firstelectro-valve being disconnected from said energy regulator by saidsafety invertor switch means if said pilot means is extinguished therebyremoving heat from said safety invertor heat responsive means.
 3. Adevice for controlling said main burner according to claim 1 whereinbi-metallic strip is heated by a resistor supplied with electric currentthrough an opening contact of the said bi-metallic strip.
 4. A devicefor controlling said main burner according to claim 1 wherein saidenergy regulator means is a bi-polar cut-out regulator.
 5. A device forcontrolling said main burner according to claim 1 wherein said energyregulator means is a single-pole cut-out regulator.
 6. A device forcontrolling said main burner according to claim 1 further comprising athermostatic temperature detection means for a device heated by saidmain burner wherein an opening contact of said thermostatic means isinserted in series in the electric feed circuit of said first gas inletelectro-valve of said main burner.
 7. A device for controlling said mainburner according to claim 4, further including a timing device insertedin a supply means for said energy regulator means.